| In seismic data processing,multiple is a key factor affecting velocity analysis and migration imaging.Effective identification and suppression of multiple is also an important means to improve interpretation accuracy.There are different kinds of multiples,so it is difficult to completely remove them by a single method.The joint suppression method is usually used,so finding a suitable method to suppress multiples is a worldwide problem,and it is also the significance of this thesis.This thesis discusses the formation,classification and recognition methods of multiples,systematically analyzes the characteristics of multiples,and puts forward the corresponding adaptive suppression method for multiples with different characteristics.In this paper,the prediction methods such as SRME and virtual in-phase axis are combined with mathematical morphology to avoid damaging the effective signal during prediction and subtraction.In addition,Radon transform is used for adaptive stratification and envelope method to extract the position of multiples and fit the time distance curve,which is convenient for adaptive morphological filtering.In addition,for some multiples close to or even aliased with the primary reflected wave,their apparent velocity,NMO correction amount and frequency are almost the same as the primary reflected wave,and their existing position is also close to the primary reflected wave.It is difficult to separate them effectively by conventional transform domain method.By introducing the parameter m,this paper proposes a T-M domain transformation method,so that the multiples which are similar to the primary reflected wave in terms of apparent velocity,shape and spatial position can be well separated in the T-M domain,and present a linear shape in the T-M domain,which is convenient to design the filter function.Finally,the effectiveness of this method is proved by the processing of simple model,strong reflection velocity model,sigsbee2 b model and actual data. |
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